Hydraulic motor and proportioning system



Aug. 4, 1964 J. x. HOGAN 3,143,138

HYDRAULIC MOTOR AND PROPORTIONING SYSTEM Filed Sept. 7, 1962 2 Sheets-Sheet 1 5 Q Lu Q m w 2 50.0: 13:07:20

H :0 is; Ir Ea q INVENTOR.

JOHN X. HOGAN JMVAL ATTORNEYS J. X. HOGAN HYDRAULIC MOTOR AND PROPORTIONING SYSTEM Aug. 4, 1964 2 Sheets-$heet 2 Filed Sept. 7, 1962 FIG. 3

FLUID Pl FLUID P2 I20 FLUID Pl I22 FLUID P2 I24 FLUID P INVENTOR.

JOHN X. HOGAN A TTORNEYS United States Patent ice 3,143,138 HYDRAULIC MOTOR AND PROPORTIONING SYSTEM John X. Hogan, 3507 Morrison St. NW., Washington, D.C. Filed Sept. 7, 1962, Ser. No. 222,031 14 Claims. (Cl. 137-567) This invention relates to hydraulic devices and more particularly to a hydraulic motor operating at an infinitely variable speed with constant torque and to a proportioning system incorporating such a motor.

In U. S. Patent No. 2,924,178 there is disclosed a vane type of proportioning unit which may be utilized either as a hydraulically or as a separately powered pump which is capable of highly accurate fixed proportioning over a large range of volume handled. In co-pending application S. N. 757,613 filed August 27, 1958, now Patent No. 3,108,541 granted October 29, 1963, is disclosed a similar proportioning pump unit which may be varied over a wide proportioning range and also a hydraulic motor, the output speed of which can be accurately controlled over a wide range.

The present application, which is a continuation-in-part of application S. N. 757,613, is directed to the novel hydraulic motor of that application and to a novel proportioning system incorporating such motors. In the novel motor of the present invention I employ a hydraulic device of the same general type as that disclosed in Patent No. 2,924,178 wherein an expansion zone is provided intermediate the main inlet and main outlet, but in the present invention the larger zone is at the inlet rather than the outlet side. The intermediate area is now more properly referred to as a compression zone. A secondary outlet is provided in the manner described herein according to the present invention and this outlet is connected to a positive displacement metering type pump.

Since the diflerence between the inlet volume of the main pump and the outlet volume must be handled by the metering pump, the volume of fluid being handled by the metering pump is determinative of the speed of rotation of the hydraulic motor. By providing a separate variable speed drive for the positive displacement metering pump, the speed of the hydraulic motor may be accurately controlled over a wide range.

Also provided is a novel proportioning system utilizing a plurality of hydraulic motors constructed in accordance with the present invention which system effects the proportioning or mixing of liquids irrespective of the pressures at which the liquids to be mixed are supplied to the system. Through the use of the novel proportioning system of the present invention, any desired proportions over an infinitely variable range of two or more liquids may be obtained as desired.

It is, therefore, one object of the present invention to provide a hydraulic unit which may be utilized as a hydraulic motor for power or control drives whose speed may be controlled accurately from zero to full speed in infinite steps.

Another object of the invention is to provide a hydraulic unit which may be utilized as a hydraulic motor whose speed is accurately variable over a wide range and which provides constant torque characteristics at all speeds.

Another object of the invention is to provide a hydrulic unit which may be utilized as a variable speed hydraulic motor of practical efiiciency and with excellent speed regulation.

Another object of the present invention is to provide a hydraulic device to control the flow of liquids from zero to design volume in infinite steps.

Still another object of the present invention is to pro- 3,143,138 Patented Aug. 4, 1964 tion will be more apparent upon reference to the following specification, claims and appended drawings wherein:

FIGURE 1 is a diagrammatic depiction of a hydraulic apparatus constructed according to one embodiment of this invention utilized as a variable speed motor;

FIGURE 2 shows a modified embodiment of the variable speed motor of FIGURE 1;

FIGURE 3 shows a system for proportioning fluids utilizing a plurality of hydraulic motors constructed in accordance with either FIGURES 1 or 2; and

FIGURE 4 shows a modified fluid-proportioning system.

Referring to the drawings, FIGURE 1 shows a first embodiment of the hydraulic unit of the present invention utilized as a variable speed motor with extended shaft for powered control drives. According to this embodiembodiment of the invention, a rotor 26 is mounted on a shaft 28 and is provided with vanes 30. For purposes of illustration FIGURE 1 shows the hydraulic motor shaft 28 extended and connected to a cable drum 29 to indicate a power or control drive. The hydraulic unit casing is concentric with the peripheral surface of the rotor over the arcuate sectors H and I with the radius of the sector H being greater than the radius of the sector I. This relationship establishes a compression zone I between sectors H and I and this Zone is connected to a secondary outlet 32. The secondary outlet 32 is connected to the inlet 34 of a positive displacement metering pump 36 having an outlet 38 and this positive displacement metering pump is driven by any variable speed non-overhauling drive 40. A valve 42 is disposed in the connection line between the secondary outlet 32 of the main hydraulic unit and the inlet 34 of the positive displacement metering pump 36.

Assuming that the metering pump is at rest and that the main hydraulic unit 20 is receiving at its inlet an incompressible fluid under a constant head, the hydraulic motor will not rotate because of the hydraulic braking action created by the compression zone I. That is to say, this unit cannot rotate unless it is possible to remove fluid therefrom at a rate that permits area I to handle a defined volume less than the defined volume of area H by the amount equal to the difference in displacements of H and I. If, now, the metering unit is operated with valve 42 open, it is possible for fluid to escape through the secondary outlet and through the positive displacement metering pump 36. That is to say, it is possible for a fluid to be removed through the secondary outlet by the positive displacement metering pump 36 in the amount equal to the difierence in displacements of H and I and the main hydraulic motor 20 will commence to rotate at a speed dependent upon the selected rate of removal of fluid from the hydraulic motor through the secondary outlet 32.

The ratio of fluid passing through sectors H and I is fixed by the physical dimensions of the motor and the ratio of fluid passing through the positive displacement metering pump to the fluid passing through either or both sectors H and I is also fixed by the relative physical dimensions of sectors H and I and the rate of displacement of the metering pump 36. A certain percentage of the fluid input to the motor 20 must be continuously removed by the secondary pump 36 in view of the fact that the outlet area I of the hydraulic motor is capable of handling less fluid than the inlet.

As an illustrative example, if the hydraulic motor Input Dis- Output Dis- Displaccplacement placement Speed merit of of Hydrauof Hydraur.p.m. of Metering lie Motor lie Motor Hydraulic Pump (H Sector) (1 Sector) Motor GaL/Min ./Min

The metering pump may be driven by any suitable variable speed non-overhauling controlled drive, such as a conventional electrical-mechanical arrangement or may be driven from the same shaft as a hydraulic motor through a variable speed control.

FIGURE 2 shows a modified embodiment of the hydraulic motor of the present invention having increased isolation for the fluid outlets. In FIGURE 2 the hydraulic motor generally indicated at 48 is enclosed in a suitable casing diagrammatically indicated by the hatch ing 49 which casing is provided with a fluid inlet 59 and a fluid outlet 52. A rotor 54 rotates. within the casing and carries a plurality of radially movable vanes 56 slideable in slots such as 58. A fluid outlet 60 carries fluid to a metering pump 62 having an outlet 64. The outlet 64 may be coupled by way of line 66 to the motor inlet 50 or alternatively to a suitable reservoir. Metering pump 62 is driven by shaft 68 from variable speed drive motor 70 by way of a variable speed nonoverhauling speed gear 72.

An arcuate channel 74 in the side of the casing communicates with the rear of the vane slots 58 in the rotor and is connected by Way of a straight channel '76 in the casing to the inlet port 50. Similar arcuate chan nels indicated by dashed lines at 78 and 80 in the easing also communicate with the slots 58 during rotation of the rotor. These latter two channels are connected together by way of a straight channel 82 and are, in turn, connected by channel 84 to the outlet 52.

The operation of the hydraulic motor in FIGURE 2 is similar to that in FIGURE 1 wherein the motor displacement in the sector defined by dashed lines B-C is greater than the displacement in the motor sector defined by dashed lines D and E. Groove or slot 74 provides fluid supply to the back of the vanes from inlet 50 to insure outward movement of the vanes. Groove 78 permits full return of the vanes through the sector E-F completing a cycle of the rotor from A to F. Similarly, groove 80 provides for partial return of the vanes during travel through the compression sector from C to D. The variable speed drive motor 70 and non-overhauling gear 72 may be of conventional types as may be the metering pump 62 and its drive.

Liquid under pressure enters through inlet 50 to fill the chamber in the sector between A and B in the area between the rotor and the casing. As the rotor turns the sector between B and C, an area of no compression and no expansion is filled. As fluid is carried to the sector between C and D the rotor will stop due to compression since the distance between the rotor and casing is less at D than at C.

As the metering pump 62 is revolved by means of drive motor '70 a quantity of liquid is removed from the sector C-D. The amount of liquid removed and the rate of its removal determines the speed and output of the rotor 54. The speed or output of the hydraulic motor 48 can, therefore, be determined by the speed and output of the metering pump. The elongated sectors defined by the areas BC and DE, respectively, are non-compression, non-expansion areas and serve to provide increased isolation of the area CD from the inlet 50 and outlet 52 respectively. Sector E-F is the discharge area of the motor.

The vanes are under the positive pressure of the incoming fluid and are forced outwardly to contact the casing 49. At B maximum displacement of the vanes is accomplished and there is no further outward or radial travel of the vanes between B and C. As the vanes approach D the confined liquid forces partial return of the vanes in the rotor slots forcing fluid in back of the vanes in slots 58 to be displaced through the series of slots 80, 82, 78 and 84 into the outlet passage 52. There is no outward or inward travel of the vanes in isolation area DE. As the vanes rotate toward F they are forced back in the rotor slots and fluid in back of each vane is forced out through slots 73 and 84 to the outlet 52.

The substantial length of isolation areas BC and DE provide increased isolation between the inlet and two outlet ports of the motor. While in the preferred embodiment, the rotor 54 carries eleven vanes 56, any number providing suitable isolation of the inlet and outlet ports of the unit may be utilized.

FIGURE 3 shows a proportioning system utilizing hydraulic motors of the type illustrated in FIGURES 1 and 2. In FIGURE 3, a pair of hydraulic motors and 92 are used to proportion a first fluid coming over line 94- at a positive pressure P1 and a second fluid coming over line 96 at a positive pressure P2 into a tank 98. The outlets 100 and 102 of the hydraulic motors corresponding to either outlet 32 of FIGURE 1 or outlet 60 of FIGURE 2 are fed to the inlets of metering pumps 108 and 110. The output from the metering pumps is fed back through lines 104 and 106 to the respective lines 94 and 96 at the input to the hydraulic motors 90 and 82.

The metering pumps 108 and 110 are driven from a common shaft by way of variable speed drive 112 and variable speed non-overhauling gears 114 and 116.

The fluids in lines 94 and 96 are supplied to the hydraulic units 90 and 92 under positive pressures P1 and P2, respectively, by suitable pumps (not shown). With the proportioning arrangement shown, any ratio of the two fluids can be provided from zero ratio to a 1:1 ratio depending upon the speed at which the metering pumps 108 and 110 are driven by motor 112. For example, if metering pumps 108 and 110 are of the same capacity and pump 108 is driven by means of its gear 114 at a faster speed than metering pump 110, the hydraulic motor 90 will rotate faster than hydraulic motor 92 and more of the fluid from line 94 will be delivered to the tank 98.

FIGURE 4 shows a modified proportioning system with like parts bearing like reference numerals. In FIGURE 4, three different fluids are supplied to tank 98 by way of lines 120, 122 and 124 at relative pressures P1, P2, and P3, respectively. A conventional positive displacement pump 126 driven by variable speed motor 112 supplies a definite capacity per minute of fluid in line to the tank 98. With the arrangement of FIGURE 4, it is possible to mix the other two fluids with the fluid in line 120 in any desired ratios. The metering pumps 108 and 110 are again driven from the common shaft which actuates pump 126 through variable speed non-overhauling gears 114 and 116 which act to control the speed of motors 90 and 92 to give the desired proportioning. By

variation of the gears 114 and 116 it is posisble to control the speed of the motors 90 and 92 so as to deliver any desired proportions of the fluids in lines 122 and 124 to the tank 98 to mix with the fluid from line 120.

It is apparent from the above that the present invention provides a novel hydraulic motor capable of providing continuous speed control from zero to a maximum design rating in infinite steps. The motor provides excellent speed regulation and constant torque characteristics at all speeds with a practical efliciency. Also provided is a novel proportioning system utilizing the hydraulic motors of the present invention which may deliver any desired ratios from zero to 1:1 in infinite steps of a plurality of fluids completely independent of the pressure at which the two or more fluids are supplied to the motors.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A hydraulic motor comprising a rotary vane positive displacement unit having a fluid circuit between a main inlet and outlet and having a second outlet therebetween, the cross sectional area of said fluid circuit being greater between said second outlet and said main inlet than between said second outlet and said main outlet, and metering pump means connected to said second outlet to remove fluid from said motor and determine its speed of rotation.

2. A hydraulic motor as set out in claim 1 wherein the cross sectional area of said fluid circuit diminishes at the position of said second outlet.

3. A hydraulic motor as set out in claim 2 wherein said unit has suflicient vanes to establish isolated columns between said second outlet and said main outlet and main inlet respectively.

4. A hydraulic motor as set out in claim 3 wherein the cross sectional area of said columns is constant along the respective columns.

5. A hydraulic motor as set out in claim 4 wherein said metering pump means comprises a rotary positive displacement type pump.

6. A hydraulic motor comprising a rotor and casing, a plurality of radially movable vanes carried by said rotor, said rotor and casing defining a fluid circuit between a main inlet and outlet and having a second outlet therebetween, the cross sectional area of said fluid circuit being greater between said second outlet and said main inlet than between said second outlet and said main outlet, and metering pump means connected to said second outlet to remove fluid from said motor and determine its speed of rotation.

7. A hydraulic motor as set out in claim 6 including variable speed drive motor means coupled to said metering pump means.

8. A hydraulic motor as set out in claim 6 wherein said vanes are mounted in slots in said rotor, said casing including first groove means for coupling said slots to said main inlet, and including second groove means for coupling said slots to said main outlet.

9. A hydraulic motor as set out in claim 6 including means coupling the output of said metering pump means to said main inlet.

10. A fluid proportioning system comprising a pair of variable speed constant torque hydraulic motors, means for supplying a first fluid at positive pressure P1 to one of said motors, means for supplying a second fluid at positive pressure F2 to the other of said motors, and means for combining the fluid outputs from said motors, each of said motors having a main outlet and a second outlet, and metering pump means connected to each of said second outlets to remove fluid from each of said motors and determine its speed.

11. A fluid proportioning system as set out in claim 10 including variable speed drive means coupled to said metering pump means.

12. A fluid proportioning system as set out in claim 11 wherein each of said motors has a main inlet, and means coupling the outlets of said metering pump means to the main inlets of said motors.

13. A fluid proportioning system comprising a pair of variable speed constant torque hydraulic motors each having a main inlet, a main outlet, and a second outlet therebetween, means for supplying a first fluid at positive pressure P1 to the main inlet of one of said motors, means for supplying a second fluid at positive pressure F2 to the main inlet of the other of said motors, means for combining the fluid outputs from the main outlets of said motors, separate metering pumps connected to the second outlet of each of said motors, a common variable speed drive for said metering pumps, and non-overhauling variable speed gears coupling each of said metering pumps to said common drive.

14. A fluid proportioning system as set out in claim 13 including a pump for supplying a third fluid to said combining means, said pump being coupled to said common drive.

References Cited in the file of this patent UNITED STATES PATENTS 2,033,219 Erle May 8, 1962 1 UNITED STATES PATENT OFFICE E CERTIFICATE OF CGRRECTION Patent No, 3,l43 l38 August 4 1964 John X Hogan It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2 line 22 strike out emlooo\i"; column 4, line 45, for "82 read 92 column 6, lines 21 and 39 for "F2" each occurrence read P2 same column 6, line 55, for "2 O83, 219" read 3,033,,219

Signed and sealed this 29th day of December 1964.,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A HYDRAULIC MOTOR COMPRISING A ROTARY VANE POSITIVE DISPLACEMENT UNIT HAVING A FLUID CIRCUIT BETWEEN A MAIN INLET AND OUTLET AND HAVING A SECOND OUTLET THEREBETWEEN, THE CROSS SECTIONAL AREA OF SAID FLUID CIRCUIT BEING GREATER BETWEEN SAID SECOND OUTLET AND SAID MAIN INLET THAN BETWEEN SAID SECOND OUTLET AND SAID MAIN OUTLET, AND METERING PUMP MEANS CONNECTED TO SAID SECOND OUTLET TO REMOVE FLUID FROM SAID MOTOR AND DETERMINE ITS SPEED OF ROTATION. 